function plotGPR_2Dlogy(x,y,x_str,y_str,varargin)

y = log(y);

if nargin == 4
    cmap = ones(numel(x),1);
    cdef = [0.4 0.6 1.0];
    %llab = {'data'};
elseif nargin == 6
    cmap = varargin{1};
    cdef = varargin{2};
    %llab = varargin{3};
else
    error('color argument mismatch');
end

U = unique(cmap);
    
color_fit = [0.1 0.3 0.2];
color_fill = [0.89 0.94 0.9];

xs = sort(x,'ascend');

covfunc = {'covSum',{'covMatern3iso','covNoise'}};
loghyper = minimize([-1;-1;-1], 'gpr', -100, covfunc, x, y);
[mu,s2] = gpr(loghyper,covfunc,x,y,xs);
%LML = -gpr(loghyper,covfunc,x,y);

fill([xs;flipdim(xs,1)],[mu-sqrt(s2);flipdim(mu+sqrt(s2),1)],color_fill,'EdgeColor',color_fill);

for i = 1:numel(U)
    u = U(i);
    ics = cmap == u;
line(x(ics),y(ics),'LineStyle','none','Marker','o','MarkerSize',2,'MarkerFaceColor',cdef(i,:),'MarkerEdgeColor',cdef(i,:));
end
%legend(llab{:});

line(xs,mu,'LineStyle','--','Color',color_fit,'LineWidth',2);
grid on;
box on;
set(gca,'Layer','top');
xlabel(x_str,'interpreter','none');
ylabel(['log(',y_str,')'],'interpreter','none');
%title(y_str);
